1. Technical Field
The claims and examples of embodiments relate to the Mobile Internet Protocol (Mobile IP) and, more particularly, to implementing direct routing.
2. Description of Related Art
Increasingly, people are connecting to the Internet using mobile devices. For example, laptop computers are used by business travelers from many locations, and cellular telephones and personal digital assistants are used by people from many locations to access information about such topics as sports and weather. To accomplish this communication, these devices typically connect—physically or wirelessly—to a network that has been established wherever they are.
To handle this mobility, a protocol known as the Mobile Internet Protocol (“Mobile IP”) was developed, enabling these mobile devices (“mobile nodes”) to maintain a static or at least semi-permanent Internet Protocol (IP) address, to which other devices can transmit data bound for the mobile nodes, no matter where the mobile nodes happen to be currently attached to the Internet. Relevant aspects of Mobile IP are described in RFC 3344, “IP Mobility Support for IPv4” (August 2002), which is incorporated herein by reference.
In Mobile IP, each mobile node has a “home network,” on which sits a device known as the mobile node's home agent (HA). Under standard IP routing, all data addressed to a mobile node will be routed to the mobile node's HA. When the mobile node is on its home network, the HA will transmit any such data to the mobile node, as would a typical router. When a mobile node is on another network, known as a “foreign network,” the mobile node informs the HA of its location. In that case, the HA transmits any data addressed to the mobile node to a device on the foreign network known as a foreign agent (FA), which delivers the data to the mobile node. The FA also routes data sent from the mobile node over the Internet to its intended destination.